Attachment for mariners&#39; compasses.



PATENTED JUNE 14, 1904. J; ROPER. ATTAGI-IMBNT FOR MARINERS GOMPAS SBS.

APPLICATION TILED DEC. 19, 1903.

2 SHEETS-SHEET 1.

N0 MODEL.

INVENTIOR Lfoa' oh Roper.

///////&

A rroxme'rs No. 762,761. 4 PATENTED JUNE 14, 1904.

I J. ROPER. f ,ATTAGHMENT FOR MARINERS GOMPASSBS;

APPLIOATION FILED DEG. 19. 1903.

N0 MODEL I 2 SHEETS-SHEET 2.

W/ TNESSES: /V VE N 70/? A Trams E rs UNITED STAT S Patented J'11116-14, 1904.

PATENT OFFICE.

ATTACHMENT FOR MARINERS COMPASSES.

SPECIFICATION forming part of Letters Patent No. 762,761, dated June 14,1904.

Application filed December 19, 1903. Serial No. 185,909. (No model.)

To all whom it may concern.-

Be it known that I, JOSEPH ROPER, a subject of the Crown of GreatBritain, and a resident of St. Johns, in the Island'of Newfoundland,have invented a certain new and useful Attachment for MarinersCompasses; and I do hereby declarethat the following is a full, clear,and exact description of the same.

My invention relates to a compass attachment for taking the bearings ofthe heavenly bodies, landmarks, lights, and distant objects, in whichavertical rod, hearing at its upper end a sighting device, operates inconjunction with an indicating-pointer on the face of the compass, so asto give the true and accurate bearing of any object when the compass isin such a position that bearings cannot be observed and noted on thecompass at one and the same timeas, for example, when the compass is inthe cabin-skylight or wheel-house, or when covered by a binnacle hood orcowl, or when a bearing is being taken at night. The objects of myimprovement are to enable bearings to be taken accurately when thecompass is in such positions as above stated, to enable accuratebearings to be taken at night, to enable the mariner to discover thedeviation of his compass by taking fixed bearings and comparing withcompass indication, to enable accurate hearings to be taken with thebinnacle without removal of binnacle or interference in any way with itshood or top, to enable hearings to be taken off pole-compasses, and todiscover by noting bearings of a fixed object from time to time how tideis setting. Devices for such purposes have heretofore been provided inwhich the sighting device was attached to a vertical rod bearing apointerarm on its lower end moving over the face of the compass.

, My invention consists in an improved construction of such device,which will be hereinafter described, and pointed out in the claims.

Figure 1 represents the instrument fitted on the binnacle. Fig. 2represents the instrument as fitted to the compass in the deck-house,wheel-house, skylight, or underdecks. Fig. 3 represents an enlargedlongitudinal section of the instrument as shown in Fig. 2. Fig.

5 O L is a plan view of the same with the vertical rod and its upperattachments removed. Fig. 5 represents a sectional detail of aweathercap to be screwed on bushing when the vertical rod is removed andthe instrument is not in use. Fig. 6 represents an enlarged longitudinalsection of the binnacle and compass as shown in Fig. 1 with myattachment applied. Fig. 7 is a plan view of the same with the verticalrod removed. Fig. 8 represents an elevation of the cross-head andattached vertical rod. Fig. 9 represents a sectional detail of thecenter pin and pointer, showing method of keeping the pointer steady.Fig. 10 represents a plan view of the center pin, showing also themethod of hanging the pointer-tip to the pointer.

Similar letters refer to similar parts throughout the several views.

The instrument may be regarded as consisting of two specific parts, thefirst part consisting of a brass arm and indicator or pointer and thesecond of a vertical rod with crosshead.

All fittings and parts of the instrument must be made of brass or some,other metal which will not influence the compass.

The description of the first part of the instrument is as follows: Tothe side of the skylight compass box or binnacle, by means of a bracketE, I attach an adjusting brass arm, which may befsimpl y horizontal or ahorizontal adjusting-arm D, in conjunction with a radial adjusting-armC, having an elbow extension passing through arm D, as shown in Figs. 3and 6. These arms are fixed in their adjustment by clamp-screws R and S.Said arms must be so adjusted that the mechanism described immediatelyhereinafter shall be exactly over the center of the compass, with thenut J at the end of it (see Fig. 9) almost touching the face of thecompass. Through the end of this arm and immediately over the center ofthe compass is put a center pin Gr, so placed as to revolve freely andyet remain perpendicular in relation to the pointer F. At the apex ofthe center pin G is a square head upon which the vertical rod A issocketed when the instrument is in use. Immediately under theabovementioned head is a collar, and between the collar and the upperside of the brass arm C is a spiral spring K. Near the bottom end of thecenter pin G is a square shank made small enough to go through a squarehole in the end of the pointer arm, upon which square shank the pointerF is socketed. Below this square shank of the pin is formed a screw ofsuch a size as to pass through the square hole in the end of the pointerF. When the pointer F is placed in position, a washer H is placed on thescrew under the pointerarm, and then a nut J is screwed on to keep thepointer F tight and in position. The spiral spring K is for the purposeof keeping the pointer F in position should the nut J work loose. To thepointer F is hinged" (see Figs. 9 and 10) a pointer-tip B, with anarticulated joint that allows it to rise, but will not allow it to fallbelow the horizontal. This tip is hinged so that the pointer-tip canadapt itself to the motion of the ship.

The second part of this machine consists of a vertical rod A, of brassor copper, which may be solid or hollow. At the lower end of this rod isformed a socket to fit on the square head at the apex of the center pinG. A slot X (see Fig. 8) is made in this rod in such a position that thepointer and tip can be observed when the vertical rod is between themand the observer. At the apex of this vertical rod is placed thecross-head T, with a tilting joint t, so that the sight-line can beelevated or depressed, as shown in dotted lines I in Fig. 6. Thiscross-head is fitted to the apex of the vertical rod A so that it isimmediately over and in exact alinement with the pointer and tip overthe face of the compass. This vertical rod is put down through thedeck-house or binnacle-top, as the case may be, through an apertureimmediately over the center of the compass. In this aperture is placed abushing M, so as to allow the vertical rod to revolve freely and yetkeep a vertical position with relation to the pointer. This bushing iskept in position by a bushing-nut N, screwed under the binnacle-top orunder the deck-house, as the case may be. The vertical rod can be keptin any desired position by the clamping-screw Q. (Shown in Fig. 6.) Whenthe instrument is not in use, the vertical rod and attachment arewithneath and sight it with the center line of the cross-head by turningthe rod A till you divide the object with the center line of thecross-head. The pointer F B will then indicate the bearing by thecompass.

A bearing can be taken off a pole-compass by-simply reversing themechanism and taking the bearing of the object from bridge or deck of avessel.

With regard to this instrument two strong features of utility are:First, it can be at-' tached to any compass or binnacle withoutalteration in any way of the compass or binnacle. Second, by being ableto take bearings off the binnacle without removal of its hood or top oropening the brass door or back of binnacle the compass is not exposed tothe weather or accident, and if being used at night binnacle-lightscannot be blown out by wind.

Having thus described my invention, What I claim as new, and desire tosecure by Letters Patent, is

1. An attachment for ships com passes, comprising a vertical shafthaving a sighting device at the top, a spring-pressed center pindetachably connected to the lower end of the shaft, an index-handattached to the center pin and means for supporting the parts,substantially as described.

2. The combination with a compass; of the index-hand B F, the elbow-armC supporting the same, the horizontal arm D supporting the elbow-arm andavertical shaft hearing at its upper end a sighting device and connectedto the index-hand.

JOSEPH ROPER.

Witnesses:

J. G. GoNRoY, JNo. MGNEELY.

